Key decoder



Feb. 9, 1937. J. w. FlTZ GERALD KEY DECODER Filed ma 1:5, 1935 v .IIIIHHIh.

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Patented Feb. 9, 1937 UNITED STATES PATENT OFFICE KEY DECODER John W. Fitz Gerald, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application May 13, 1935, Serial No. 21,280

4 Claims. 33-174) This invention relates to improvements in Referring now more particularly to the ackey decoders and has as an object to provide companying drawing, in which like numerals a simple and effective device for checking or indicate like parts throughout the several views, decoding the combination of a key. it will be seen that the device consists of a More specifically it is an object of this invenbody 5 which may take the form of a conven- 5 tion to provide means for checking or decoding tional cylinder, as shown, provided with a keythe combination of keys cut as described in the way 6 into which a key I to be decoded is inco-pending application of Raymond W. Griffith, sertable. As in a conventional lock cylinder, Serial No. 15,269, filed April 8, 1935. tumblers 8 are mounted in the body 5 with their With the above and other objects in view key engaging portions 9 accessible from the key- 10 which will appear as the description proceeds, way 6 to be engaged by the blade ID of the key. this invention resides in the novel construction, Each tumbler has an individual spring H combination and arrangement of parts substanpressing it down into its respective pocket so tially as hereinafter described and more parthat upon the insertion of the key, the tumblers ticularly defined by the appended claims, it are lifted against the action of their springs. 15 being understood that such changes in the pre- All of the springs are conveniently held in cise embodiment of the hereindisclosed invention place by a plate I2 having an angular extension may be made as come within the scope of the I 3 received in a slot l4 cut into the body 5 claims. and held therein by a rivet I5. As shown, the

The accompanying drawing illustrates one plate l2 extends longitudinally across the tumcomplete example of the physical embodiment bler receiving pockets of the body 5 in position of the invention constructed according to the to be engaged by the outer ends of all of the best mode so far devised for the practical springs. application of the principles thereof, and in The plate l2 forms substantially a fin extendwhich: ing radially from the top of the body 5 in line 25 Figure 1 is a view in side elevation showing with the motion of the tumblers imparted the complete decoder and its manner of use, thereto by the key. The tumblers are provided parts thereof being broken away; with upward extensions I6 which overlie the Figure 2 is a cross section view taken through front of the plate 12 to move up over the plate Figure 1 on the plane of the line 2--2; and to heights determined by the contour of the key.

Figure 3 is an enlarged fragmentary detail The plate I2 may have indicia formed directly View. on its front face cooperable with the'projecting As defined in detail in the aforesaid co-pendends 16 of the tumblers to enable the combinaing application, the locks with which this intion of the key to be visually depicted, or as in vention and said co-pending application are the present instance, a separate indicator plate 35 concerned, have their code combinations desig- I! having such indicia may be secured to the nated by numerals and letters. The numerals front face of the plate i2. In any event, there 1 to 6, inclusive, refer to the positions of the are four superimposed stripes i8, i9, 2%! and .2! tumblers in the cylinder, and the letters C, B, paralleling the axis of the body and so disposed 40 N and Y, designating the colors copper, black, that the projecting tumbler ends [6 are lifted 40 nickel and yellow, refer to the depth of the key to align with these stripes upon insertion of engaging portions of the tumblers. the key.

Assuming that a cylinder has the combina- The stripes IS, I9, 20 and 2| are respectively tion colored yellow, black, nickel and copper and to 1-- one side the letter designations Y, B, N and C 45 are also: delineated on the plate Il, preferably a key to fit this combination is easily cut by in their respective colors with lead lines connectmeans of the key cutting fixture forming the the letter designations respective subject matter of the aforesaid co-pending ap- Stripes 99, 29 and c m To check t correctness of t key Above the stripes and in line with the tumblers as cut is the purpose of this invention. Of are the numerical designatiel'ls 3, 5 a d course, it may also be used to ascertain the com- 5, representing the different positions of e bination of any key already cut for purposes of tu blers in t e 100k. duplication or the fitting of a lock cylinder As will be readily apparent, to use the device thereto. it is only necessary to insert the key into the 55 contour of the key, the degree of motion being indicated by the projecting upper ends E6 of the tumblers moving into register with the stripes l8, i9, 20 and 2|. The entire combination is thus visually depicted by the location of the upper ends of the tumblers with respect to these stripes.

What I claim as my invention is:

1. A key decoding device comprising a body having a keyway adapted to receive a key, spring pressed tumblers mounted in the body and adapted to be lifted to difierent heights against the action of their springs by a key inserted into the keyway, end portions on the tumblers projectible from the body to heights corresponding to the distances the tumblers are lifted by the key, a part carried by the body and having a surface across which the projecting end portions of the'tumblers move, and side by side stripes representing difierent tumbler depths delineated on said surface transversely across the paths of the tumbler end portions to cooperate therewith and indicate the combination of the key.

2. A key decoder of the character described comprising a body having a keyway into which a key to be decoded is insertable, tumblers movable in the body by a key inserted into the keyway, indicating portions forming an integral part of the tumblers projectible from the body, an indicator plate carried by the body and disposed in a plane parallel to the motion of the tumblers and so disposed that the indicating portions of the tumblers move across said plate,

and indicia on the plate cooperable directly with the indicating portions of the tumblers to depict the combination of a key inserted into the keyway.

3. A key decoder of the character described comprising a body having a keyway to receive a key to be decoded, a plurality of tumblers mounted in the body-and movable by a key inserted into the keyway, springs for the tumblers to yieldingly maintain the tumblers in predetermined positions from which they are moved by the key, a plate carried by the body and having a portion forming an abutment for the springs to hold the springs and tumblers in the body, said plate being disposed in the plane of movement of the tumblers, indicating portions on the tumblers movable across said plate, and indicia on the plate cooperable with the indicating portions of the tumblers to indicate the difierent heights to which the tumblers are moved by a key inserted into the keyway so that the combination of the key is determinable by the position of the indicating portions with respect to said indicia.

4. A key decoder of the character described comprising a body having a keyway to receive a key to be decoded, a plurality of tumblers mounted in the body and movable by a key inserted in the keyway, said tumblers having a stepped end portion part of which projects from the body, a spring engaging the step of each tumbler to yieldingly maintain the same in a predetermined position from which it is moved by the key, a plate carried by the body in line with the stepped ends of the tumblers with one edge engaging the springs to hold the same and the tumblers in the body, said plate being so disposed that said projecting parts of the tumblers move flatwise thereacross, and a plurality of indicating lines delineated on the plate across the paths of said tumbler parts to cooperate therewith and indicate the diiferent heights to which the tumblers are moved by a key inserted into the keyway.

JOHN W. FITZ GERALD. 

